RDMA: Restore ability to fail on AH destroy

Like any other IB verbs objects, AH are refcounted by ib_core. The release
of those objects are controlled by ib_core with promise that AH destroy
can't fail.

Being SW object for now, this change makes dealloc_ah() to behave like any
other destroy IB flows.

Fixes: d345691471b4 ("RDMA: Handle AH allocations by IB/core")
Link: https://lore.kernel.org/r/20200907120921.476363-3-leon@kernel.org
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
diff --git a/drivers/infiniband/core/verbs.c b/drivers/infiniband/core/verbs.c
index a4a2cd37..bd345e7 100644
--- a/drivers/infiniband/core/verbs.c
+++ b/drivers/infiniband/core/verbs.c
@@ -968,18 +968,22 @@ int rdma_destroy_ah_user(struct ib_ah *ah, u32 flags, struct ib_udata *udata)
 {
 	const struct ib_gid_attr *sgid_attr = ah->sgid_attr;
 	struct ib_pd *pd;
+	int ret;
 
 	might_sleep_if(flags & RDMA_DESTROY_AH_SLEEPABLE);
 
 	pd = ah->pd;
 
-	ah->device->ops.destroy_ah(ah, flags);
+	ret = ah->device->ops.destroy_ah(ah, flags);
+	if (ret)
+		return ret;
+
 	atomic_dec(&pd->usecnt);
 	if (sgid_attr)
 		rdma_put_gid_attr(sgid_attr);
 
 	kfree(ah);
-	return 0;
+	return ret;
 }
 EXPORT_SYMBOL(rdma_destroy_ah_user);
 
diff --git a/drivers/infiniband/hw/bnxt_re/ib_verbs.c b/drivers/infiniband/hw/bnxt_re/ib_verbs.c
index c53f6e3..67ebf19 100644
--- a/drivers/infiniband/hw/bnxt_re/ib_verbs.c
+++ b/drivers/infiniband/hw/bnxt_re/ib_verbs.c
@@ -602,13 +602,14 @@ int bnxt_re_alloc_pd(struct ib_pd *ibpd, struct ib_udata *udata)
 }
 
 /* Address Handles */
-void bnxt_re_destroy_ah(struct ib_ah *ib_ah, u32 flags)
+int bnxt_re_destroy_ah(struct ib_ah *ib_ah, u32 flags)
 {
 	struct bnxt_re_ah *ah = container_of(ib_ah, struct bnxt_re_ah, ib_ah);
 	struct bnxt_re_dev *rdev = ah->rdev;
 
 	bnxt_qplib_destroy_ah(&rdev->qplib_res, &ah->qplib_ah,
 			      !(flags & RDMA_DESTROY_AH_SLEEPABLE));
+	return 0;
 }
 
 static u8 bnxt_re_stack_to_dev_nw_type(enum rdma_network_type ntype)
diff --git a/drivers/infiniband/hw/bnxt_re/ib_verbs.h b/drivers/infiniband/hw/bnxt_re/ib_verbs.h
index d9e2e40..b6b56a9 100644
--- a/drivers/infiniband/hw/bnxt_re/ib_verbs.h
+++ b/drivers/infiniband/hw/bnxt_re/ib_verbs.h
@@ -168,7 +168,7 @@ int bnxt_re_create_ah(struct ib_ah *ah, struct rdma_ah_init_attr *init_attr,
 		      struct ib_udata *udata);
 int bnxt_re_modify_ah(struct ib_ah *ah, struct rdma_ah_attr *ah_attr);
 int bnxt_re_query_ah(struct ib_ah *ah, struct rdma_ah_attr *ah_attr);
-void bnxt_re_destroy_ah(struct ib_ah *ah, u32 flags);
+int bnxt_re_destroy_ah(struct ib_ah *ah, u32 flags);
 int bnxt_re_create_srq(struct ib_srq *srq,
 		       struct ib_srq_init_attr *srq_init_attr,
 		       struct ib_udata *udata);
diff --git a/drivers/infiniband/hw/efa/efa.h b/drivers/infiniband/hw/efa/efa.h
index 8547f9d..6b06ce8 100644
--- a/drivers/infiniband/hw/efa/efa.h
+++ b/drivers/infiniband/hw/efa/efa.h
@@ -156,7 +156,7 @@ void efa_mmap_free(struct rdma_user_mmap_entry *rdma_entry);
 int efa_create_ah(struct ib_ah *ibah,
 		  struct rdma_ah_init_attr *init_attr,
 		  struct ib_udata *udata);
-void efa_destroy_ah(struct ib_ah *ibah, u32 flags);
+int efa_destroy_ah(struct ib_ah *ibah, u32 flags);
 int efa_modify_qp(struct ib_qp *ibqp, struct ib_qp_attr *qp_attr,
 		  int qp_attr_mask, struct ib_udata *udata);
 enum rdma_link_layer efa_port_link_layer(struct ib_device *ibdev,
diff --git a/drivers/infiniband/hw/efa/efa_verbs.c b/drivers/infiniband/hw/efa/efa_verbs.c
index 383ce12..a03e351 100644
--- a/drivers/infiniband/hw/efa/efa_verbs.c
+++ b/drivers/infiniband/hw/efa/efa_verbs.c
@@ -1873,7 +1873,7 @@ int efa_create_ah(struct ib_ah *ibah,
 	return err;
 }
 
-void efa_destroy_ah(struct ib_ah *ibah, u32 flags)
+int efa_destroy_ah(struct ib_ah *ibah, u32 flags)
 {
 	struct efa_dev *dev = to_edev(ibah->pd->device);
 	struct efa_ah *ah = to_eah(ibah);
@@ -1883,10 +1883,11 @@ void efa_destroy_ah(struct ib_ah *ibah, u32 flags)
 	if (!(flags & RDMA_DESTROY_AH_SLEEPABLE)) {
 		ibdev_dbg(&dev->ibdev,
 			  "Destroy address handle is not supported in atomic context\n");
-		return;
+		return -EOPNOTSUPP;
 	}
 
 	efa_ah_destroy(dev, ah);
+	return 0;
 }
 
 struct rdma_hw_stats *efa_alloc_hw_stats(struct ib_device *ibdev, u8 port_num)
diff --git a/drivers/infiniband/hw/hns/hns_roce_ah.c b/drivers/infiniband/hw/hns/hns_roce_ah.c
index 54cadbc..75b06db 100644
--- a/drivers/infiniband/hw/hns/hns_roce_ah.c
+++ b/drivers/infiniband/hw/hns/hns_roce_ah.c
@@ -116,8 +116,3 @@ int hns_roce_query_ah(struct ib_ah *ibah, struct rdma_ah_attr *ah_attr)
 
 	return 0;
 }
-
-void hns_roce_destroy_ah(struct ib_ah *ah, u32 flags)
-{
-	return;
-}
diff --git a/drivers/infiniband/hw/hns/hns_roce_device.h b/drivers/infiniband/hw/hns/hns_roce_device.h
index 9688240..da3e8ed 100644
--- a/drivers/infiniband/hw/hns/hns_roce_device.h
+++ b/drivers/infiniband/hw/hns/hns_roce_device.h
@@ -1179,7 +1179,10 @@ void hns_roce_bitmap_free_range(struct hns_roce_bitmap *bitmap,
 int hns_roce_create_ah(struct ib_ah *ah, struct rdma_ah_init_attr *init_attr,
 		       struct ib_udata *udata);
 int hns_roce_query_ah(struct ib_ah *ibah, struct rdma_ah_attr *ah_attr);
-void hns_roce_destroy_ah(struct ib_ah *ah, u32 flags);
+static inline int hns_roce_destroy_ah(struct ib_ah *ah, u32 flags)
+{
+	return 0;
+}
 
 int hns_roce_alloc_pd(struct ib_pd *pd, struct ib_udata *udata);
 int hns_roce_dealloc_pd(struct ib_pd *pd, struct ib_udata *udata);
diff --git a/drivers/infiniband/hw/mlx4/ah.c b/drivers/infiniband/hw/mlx4/ah.c
index 5f8f8d5..7321d6a 100644
--- a/drivers/infiniband/hw/mlx4/ah.c
+++ b/drivers/infiniband/hw/mlx4/ah.c
@@ -232,8 +232,3 @@ int mlx4_ib_query_ah(struct ib_ah *ibah, struct rdma_ah_attr *ah_attr)
 
 	return 0;
 }
-
-void mlx4_ib_destroy_ah(struct ib_ah *ah, u32 flags)
-{
-	return;
-}
diff --git a/drivers/infiniband/hw/mlx4/mlx4_ib.h b/drivers/infiniband/hw/mlx4/mlx4_ib.h
index bcac8fc..6d51653 100644
--- a/drivers/infiniband/hw/mlx4/mlx4_ib.h
+++ b/drivers/infiniband/hw/mlx4/mlx4_ib.h
@@ -753,7 +753,10 @@ int mlx4_ib_create_ah(struct ib_ah *ah, struct rdma_ah_init_attr *init_attr,
 int mlx4_ib_create_ah_slave(struct ib_ah *ah, struct rdma_ah_attr *ah_attr,
 			    int slave_sgid_index, u8 *s_mac, u16 vlan_tag);
 int mlx4_ib_query_ah(struct ib_ah *ibah, struct rdma_ah_attr *ah_attr);
-void mlx4_ib_destroy_ah(struct ib_ah *ah, u32 flags);
+static inline int mlx4_ib_destroy_ah(struct ib_ah *ah, u32 flags)
+{
+	return 0;
+}
 
 int mlx4_ib_create_srq(struct ib_srq *srq, struct ib_srq_init_attr *init_attr,
 		       struct ib_udata *udata);
diff --git a/drivers/infiniband/hw/mlx5/ah.c b/drivers/infiniband/hw/mlx5/ah.c
index 4a60e69..505bc47 100644
--- a/drivers/infiniband/hw/mlx5/ah.c
+++ b/drivers/infiniband/hw/mlx5/ah.c
@@ -147,8 +147,3 @@ int mlx5_ib_query_ah(struct ib_ah *ibah, struct rdma_ah_attr *ah_attr)
 
 	return 0;
 }
-
-void mlx5_ib_destroy_ah(struct ib_ah *ah, u32 flags)
-{
-	return;
-}
diff --git a/drivers/infiniband/hw/mlx5/mlx5_ib.h b/drivers/infiniband/hw/mlx5/mlx5_ib.h
index 5287fc8..1e5f77d 100644
--- a/drivers/infiniband/hw/mlx5/mlx5_ib.h
+++ b/drivers/infiniband/hw/mlx5/mlx5_ib.h
@@ -1119,7 +1119,10 @@ void mlx5_ib_free_srq_wqe(struct mlx5_ib_srq *srq, int wqe_index);
 int mlx5_ib_create_ah(struct ib_ah *ah, struct rdma_ah_init_attr *init_attr,
 		      struct ib_udata *udata);
 int mlx5_ib_query_ah(struct ib_ah *ibah, struct rdma_ah_attr *ah_attr);
-void mlx5_ib_destroy_ah(struct ib_ah *ah, u32 flags);
+static inline int mlx5_ib_destroy_ah(struct ib_ah *ah, u32 flags)
+{
+	return 0;
+}
 int mlx5_ib_create_srq(struct ib_srq *srq, struct ib_srq_init_attr *init_attr,
 		       struct ib_udata *udata);
 int mlx5_ib_modify_srq(struct ib_srq *ibsrq, struct ib_srq_attr *attr,
diff --git a/drivers/infiniband/hw/mthca/mthca_provider.c b/drivers/infiniband/hw/mthca/mthca_provider.c
index d3ed7c1..12b7c53 100644
--- a/drivers/infiniband/hw/mthca/mthca_provider.c
+++ b/drivers/infiniband/hw/mthca/mthca_provider.c
@@ -390,9 +390,10 @@ static int mthca_ah_create(struct ib_ah *ibah,
 			       init_attr->ah_attr, ah);
 }
 
-static void mthca_ah_destroy(struct ib_ah *ah, u32 flags)
+static int mthca_ah_destroy(struct ib_ah *ah, u32 flags)
 {
 	mthca_destroy_ah(to_mdev(ah->device), to_mah(ah));
+	return 0;
 }
 
 static int mthca_create_srq(struct ib_srq *ibsrq,
diff --git a/drivers/infiniband/hw/ocrdma/ocrdma_ah.c b/drivers/infiniband/hw/ocrdma/ocrdma_ah.c
index 6eea02b..699a8b7 100644
--- a/drivers/infiniband/hw/ocrdma/ocrdma_ah.c
+++ b/drivers/infiniband/hw/ocrdma/ocrdma_ah.c
@@ -215,12 +215,13 @@ int ocrdma_create_ah(struct ib_ah *ibah, struct rdma_ah_init_attr *init_attr,
 	return status;
 }
 
-void ocrdma_destroy_ah(struct ib_ah *ibah, u32 flags)
+int ocrdma_destroy_ah(struct ib_ah *ibah, u32 flags)
 {
 	struct ocrdma_ah *ah = get_ocrdma_ah(ibah);
 	struct ocrdma_dev *dev = get_ocrdma_dev(ibah->device);
 
 	ocrdma_free_av(dev, ah);
+	return 0;
 }
 
 int ocrdma_query_ah(struct ib_ah *ibah, struct rdma_ah_attr *attr)
diff --git a/drivers/infiniband/hw/ocrdma/ocrdma_ah.h b/drivers/infiniband/hw/ocrdma/ocrdma_ah.h
index 8b73b34..35cf2e2f 100644
--- a/drivers/infiniband/hw/ocrdma/ocrdma_ah.h
+++ b/drivers/infiniband/hw/ocrdma/ocrdma_ah.h
@@ -53,7 +53,7 @@ enum {
 
 int ocrdma_create_ah(struct ib_ah *ah, struct rdma_ah_init_attr *init_attr,
 		     struct ib_udata *udata);
-void ocrdma_destroy_ah(struct ib_ah *ah, u32 flags);
+int ocrdma_destroy_ah(struct ib_ah *ah, u32 flags);
 int ocrdma_query_ah(struct ib_ah *ah, struct rdma_ah_attr *ah_attr);
 
 int ocrdma_process_mad(struct ib_device *dev, int process_mad_flags,
diff --git a/drivers/infiniband/hw/qedr/verbs.c b/drivers/infiniband/hw/qedr/verbs.c
index c81d1e5..f85e916 100644
--- a/drivers/infiniband/hw/qedr/verbs.c
+++ b/drivers/infiniband/hw/qedr/verbs.c
@@ -2767,11 +2767,12 @@ int qedr_create_ah(struct ib_ah *ibah, struct rdma_ah_init_attr *init_attr,
 	return 0;
 }
 
-void qedr_destroy_ah(struct ib_ah *ibah, u32 flags)
+int qedr_destroy_ah(struct ib_ah *ibah, u32 flags)
 {
 	struct qedr_ah *ah = get_qedr_ah(ibah);
 
 	rdma_destroy_ah_attr(&ah->attr);
+	return 0;
 }
 
 static void free_mr_info(struct qedr_dev *dev, struct mr_info *info)
diff --git a/drivers/infiniband/hw/qedr/verbs.h b/drivers/infiniband/hw/qedr/verbs.h
index 1b45091..1b4ed8d 100644
--- a/drivers/infiniband/hw/qedr/verbs.h
+++ b/drivers/infiniband/hw/qedr/verbs.h
@@ -72,7 +72,7 @@ int qedr_post_srq_recv(struct ib_srq *ibsrq, const struct ib_recv_wr *wr,
 		       const struct ib_recv_wr **bad_recv_wr);
 int qedr_create_ah(struct ib_ah *ibah, struct rdma_ah_init_attr *init_attr,
 		   struct ib_udata *udata);
-void qedr_destroy_ah(struct ib_ah *ibah, u32 flags);
+int qedr_destroy_ah(struct ib_ah *ibah, u32 flags);
 
 int qedr_dereg_mr(struct ib_mr *ib_mr, struct ib_udata *udata);
 struct ib_mr *qedr_get_dma_mr(struct ib_pd *, int acc);
diff --git a/drivers/infiniband/hw/vmw_pvrdma/pvrdma_verbs.c b/drivers/infiniband/hw/vmw_pvrdma/pvrdma_verbs.c
index 678c945..fc412cb 100644
--- a/drivers/infiniband/hw/vmw_pvrdma/pvrdma_verbs.c
+++ b/drivers/infiniband/hw/vmw_pvrdma/pvrdma_verbs.c
@@ -548,9 +548,10 @@ int pvrdma_create_ah(struct ib_ah *ibah, struct rdma_ah_init_attr *init_attr,
  * @flags: destroy address handle flags (see enum rdma_destroy_ah_flags)
  *
  */
-void pvrdma_destroy_ah(struct ib_ah *ah, u32 flags)
+int pvrdma_destroy_ah(struct ib_ah *ah, u32 flags)
 {
 	struct pvrdma_dev *dev = to_vdev(ah->device);
 
 	atomic_dec(&dev->num_ahs);
+	return 0;
 }
diff --git a/drivers/infiniband/hw/vmw_pvrdma/pvrdma_verbs.h b/drivers/infiniband/hw/vmw_pvrdma/pvrdma_verbs.h
index 7bf33a6..58b41a3 100644
--- a/drivers/infiniband/hw/vmw_pvrdma/pvrdma_verbs.h
+++ b/drivers/infiniband/hw/vmw_pvrdma/pvrdma_verbs.h
@@ -416,7 +416,7 @@ int pvrdma_poll_cq(struct ib_cq *ibcq, int num_entries, struct ib_wc *wc);
 int pvrdma_req_notify_cq(struct ib_cq *cq, enum ib_cq_notify_flags flags);
 int pvrdma_create_ah(struct ib_ah *ah, struct rdma_ah_init_attr *init_attr,
 		     struct ib_udata *udata);
-void pvrdma_destroy_ah(struct ib_ah *ah, u32 flags);
+int pvrdma_destroy_ah(struct ib_ah *ah, u32 flags);
 
 int pvrdma_create_srq(struct ib_srq *srq, struct ib_srq_init_attr *init_attr,
 		      struct ib_udata *udata);
diff --git a/drivers/infiniband/sw/rdmavt/ah.c b/drivers/infiniband/sw/rdmavt/ah.c
index 75a04b1..b938c4f 100644
--- a/drivers/infiniband/sw/rdmavt/ah.c
+++ b/drivers/infiniband/sw/rdmavt/ah.c
@@ -132,7 +132,7 @@ int rvt_create_ah(struct ib_ah *ibah, struct rdma_ah_init_attr *init_attr,
  *
  * Return: 0 on success
  */
-void rvt_destroy_ah(struct ib_ah *ibah, u32 destroy_flags)
+int rvt_destroy_ah(struct ib_ah *ibah, u32 destroy_flags)
 {
 	struct rvt_dev_info *dev = ib_to_rvt(ibah->device);
 	struct rvt_ah *ah = ibah_to_rvtah(ibah);
@@ -143,6 +143,7 @@ void rvt_destroy_ah(struct ib_ah *ibah, u32 destroy_flags)
 	spin_unlock_irqrestore(&dev->n_ahs_lock, flags);
 
 	rdma_destroy_ah_attr(&ah->attr);
+	return 0;
 }
 
 /**
diff --git a/drivers/infiniband/sw/rdmavt/ah.h b/drivers/infiniband/sw/rdmavt/ah.h
index 40b7123..5a85edd 100644
--- a/drivers/infiniband/sw/rdmavt/ah.h
+++ b/drivers/infiniband/sw/rdmavt/ah.h
@@ -52,7 +52,7 @@
 
 int rvt_create_ah(struct ib_ah *ah, struct rdma_ah_init_attr *init_attr,
 		  struct ib_udata *udata);
-void rvt_destroy_ah(struct ib_ah *ibah, u32 destroy_flags);
+int rvt_destroy_ah(struct ib_ah *ibah, u32 destroy_flags);
 int rvt_modify_ah(struct ib_ah *ibah, struct rdma_ah_attr *ah_attr);
 int rvt_query_ah(struct ib_ah *ibah, struct rdma_ah_attr *ah_attr);
 
diff --git a/drivers/infiniband/sw/rxe/rxe_verbs.c b/drivers/infiniband/sw/rxe/rxe_verbs.c
index 7fe7316..c346b02 100644
--- a/drivers/infiniband/sw/rxe/rxe_verbs.c
+++ b/drivers/infiniband/sw/rxe/rxe_verbs.c
@@ -201,11 +201,12 @@ static int rxe_query_ah(struct ib_ah *ibah, struct rdma_ah_attr *attr)
 	return 0;
 }
 
-static void rxe_destroy_ah(struct ib_ah *ibah, u32 flags)
+static int rxe_destroy_ah(struct ib_ah *ibah, u32 flags)
 {
 	struct rxe_ah *ah = to_rah(ibah);
 
 	rxe_drop_ref(ah);
+	return 0;
 }
 
 static int post_one_recv(struct rxe_rq *rq, const struct ib_recv_wr *ibwr)
diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h
index a49aaeb..71b145f 100644
--- a/include/rdma/ib_verbs.h
+++ b/include/rdma/ib_verbs.h
@@ -2403,7 +2403,7 @@ struct ib_device_ops {
 			 struct ib_udata *udata);
 	int (*modify_ah)(struct ib_ah *ah, struct rdma_ah_attr *ah_attr);
 	int (*query_ah)(struct ib_ah *ah, struct rdma_ah_attr *ah_attr);
-	void (*destroy_ah)(struct ib_ah *ah, u32 flags);
+	int (*destroy_ah)(struct ib_ah *ah, u32 flags);
 	int (*create_srq)(struct ib_srq *srq,
 			  struct ib_srq_init_attr *srq_init_attr,
 			  struct ib_udata *udata);
@@ -3596,9 +3596,11 @@ int rdma_destroy_ah_user(struct ib_ah *ah, u32 flags, struct ib_udata *udata);
  *
  * NOTE: for user ah use rdma_destroy_ah_user with valid udata!
  */
-static inline int rdma_destroy_ah(struct ib_ah *ah, u32 flags)
+static inline void rdma_destroy_ah(struct ib_ah *ah, u32 flags)
 {
-	return rdma_destroy_ah_user(ah, flags, NULL);
+	int ret = rdma_destroy_ah_user(ah, flags, NULL);
+
+	WARN_ONCE(ret, "Destroy of kernel AH shouldn't fail");
 }
 
 struct ib_srq *ib_create_srq_user(struct ib_pd *pd,